Apparatus for generating pulsed jets of liquid

ABSTRACT

Apparatus for generating pulsed jets of liquid or gel charge material. An expulsion barrel has a charge inlet, a charge storage area, a charge outlet and a valve zone coupling the charge storage area with the charge inlet and the charge outlet. A valve within the valve zone moves under pressure from the charge inlet to a position in which charge material is permitted to pass from the inlet to the charge storage area, while being blocked from the charge outlet, and under pressure from the charge storage area due to action of a piston to a position in which charge material is permitted to pass from the storage area to the charge outlet, while being blocked from the charge inlet. In this manner, the expulsion barrel is dry between jets which provides for a higher pressure jet. A improved seal prevents charge material from escaping around the piston. The seal includes a non-resilient portion interfacing with the piston during piston movement and a resilient portion placed between this non-resilient portion and the surrounding housing and which is compressed due to applied pressure from the charge material to seal the non-resilient portion and the piston thereby assuring a leak-proof seal.

il'nited States Patent Clipp et al.

1541 APPARATUS FOR GENERATING PULSED JETS or LIQUID [72] Inventors: James M. Hall, Caithersburg, Md.; Louis L. Clipp, McLean, Va.

[73] Assignees Exotech Incorporated, Gaithersburg,

[22] Filed: Aprill9, 1971 21 Appl. No.: 135,119

52 us. (:1 ..239/102 51 Int. Cl. ..B05b3/l4 581 Field of Search ..239/99, 101, 102 329, 4 55,

[451 Jan. 23, 1973 Primary Examiner-M. Henson Wood, Jr.

Assistant Examiner-Edwin D. Grant Attorney-John W. Behringer, John T. Roberts, Malcolm L. Sutherland, John W. Behrin'ger, Eugene L. Bernard, Martin J. Brown, James N. Dresser, W. Brown Morton, Jr., John T. Roberts and Malcolm L. Sutherland [57] ABSTRACT Apparatus for generating pulsed jets of liquid or gel charge material. An expulsion barrel has a charge inlet, a charge storage area, a charge outlet and a valve zone coupling the charge storage area with the charge inlet and the charge outlet. A valve within the valve zone moves under pressure from the charge inlet to a position in which charge material is permitted to pass from the inlet to the charge storage area, while being blocked from the charge outlet, and under pressure from the charge storage area due to action of a piston to a position in which charge material is permitted to pass from the storage area to the charge outlet, while being blocked from the charge inlet; in this manner, the expulsion barrel is dry between jets which provides for a hi g lier pre ssure jet. An improved seal prevents charge material from escaping around the piston. The seal mantles a non-resiBent portion interfacing with the piston during piston movement and a resilient portion placed between this non-resilient portion and the surrounding housing and which is compressed due to applied pressure from the charge material to seal the non-resilient portion and the piston thereby assuring a leak-proof seal.

8 Claims, 12 Drawing Figures SHEET 1 OF 3 PATENTED-JM 23 "r975 INVENTORS JAMES M. HALL 8| LOUIS CLI PP mm N 77% MQAZ ZZZJ ATTORNEYS PMENTEnJMwms 3.712.543

SHEET 3 OF 3 90 a2 a4 92- as ENT JAMES AL LOUIS CLIPP ATTORNE Y5 APPARATUS FOR GENERATING PULSED JETS OF LIQUID The present invention pertains to apparatus for producing high velocity jet pulses of liquid or gel at high stagnation pressure, i.e. 300,000 to 500,000 p.s.i. or more. More particularly, the present invention pertains to apparatus for producing pulsed jets of liquid or gel and including improved valving means and sealing means for metering liquid or gel charge material properly during operation of the apparatus while preventing leaking of the charge material within the apparatus.

Pulsed jets of liquid are useful for such operations as cutting metal and fracturing rock. Pulsed jets can be generated by several means. Cumulation and shaped charge techniques have been used, but the expense and the hazards associated with explosive materials have limited their use. Piston expulsion of liquid or gel is frequently utilized, but difficulties have been encountered in piston sealing and leakage, in view of the high pressures required.

The present invention is an apparatus for generating pulsed jets of liquid or gel material by piston expulsion of a charge of such material and including improved valve and sealing means for preventing leakage of liquid or gel into those areas of the interior of the apparatus from which such material is preferably exluded while permitting loading of desired quantities of the material from a charge inlet into the charge-loading area of the apparatus and expulsion of the material through a charge outlet. In accordance with the present invention there is provided apparatus including an expulsion barrel having a charge inlet, a charge storage area, a valve zone coupled to said charge storage area, a charge outlet, a first charge transmission passage coupling the charge inlet with the valve zone, a second charge transmission passage coupling the valve zone with the charge outlet, valve means within the valve zone and movable in response to pressure within the firstcharge transmission passage to a first position in which the charge is permitted to pass from the first charge transmission passage to the charge storage area andin response to pressure within the charge storage area to a second position in which the charge is permitted to'pass from the charge storage area to the second charge transmission passage and hence to the charge outlet, piston means for applying pressure to charge within the charge storage area, and seal means for providing a substantially fluid-tight seal between the barrel interior surface and the piston so that charge material is not permitted topass from the charge storage area to other areas on the interior of the apparatus. Preferably, the valve means is an annular ring positioned substantially symmetrically about the expulsion barrel longitudinal axis and having one or more openings therethrough from one face to the other. Preferably, the seal means is an annular ring including a first portion of a substantially rigid, non-resilient material such as metal and a second portion of a resilient material which acts against the first portion as the piston means moves to expel the charge with the result that the first, non-resilient portion is pressed against the piston to increase the seal, thereby assuring that charge material does not leak past the piston means.

These and other aspects and advantages of the present invention are apparent in the following detailed description and claims, particularly when read in conjunction with the accompanying drawings in which like parts bear like reference numerals. In the drawings:

FIG. 1 is a fragmentary sectional view of apparatus in accordance with the present invention and is taken along line 11 ofFIG. 3;

FIG. 2 is an enlarged fragmentary sectional view of portion 2-2 of FIG. 1 depicting seal means preferred for use in the present invention with the piston means in its rest position;

FIG. 3 is a view taken along line 33 of FIG. 1;

FIG. 4 is an enlarged fragmentary view of portion 44 of FIG. 1 depicting valve means preferred for use in the present invention during expulsion of a pulsed jet from the apparatus;

FIG. 5 is a view similar to FIG. 4 but depicting the valve means positioned for loading of charge into the apparatus;

FIGS. 6a and 6b illustrate the use of a deflection plate with apparatus in accordance with the present invention;

FIGS. 7a and 7b illustrate an alternative means for deflecting the jet produced by apparatus of this invention;

FIG. 8 illustrates apparatus of this invention including means for flushing the jet nozzle to prevent p g;

FIG. 0 illustrates apparatus of this invention designed for underwater use; and

FIG. 10 illustrates a modified embodiment of apparatus in accordance with the presentinvention.

As seen in FIG. I, the apparatus 10 of the present invention, which is capable of generating pulsed jets of liquid or gel material and which can be considered a water cannon, includes an outer housing 12 and an inner housing 14 held together by coupling member 16 and retainer, i.e., pin 18 which extends as a chord through member 16 and housing 14 and is preferably of non-resilient material such as steeLCoupling member 16 is fastened to inner housing 14 for example by threads 20. The outer surface of coupling member 16 adjacent retainer pin 18 includes groove 22 which permits coupling member 16 and inner housing 14 to move longitudinally with respect to outer housing 12. The rearward end 24 of groove 22 cooperates with retainer 18 to prevent coupling member 16 and inner housing 14 from completely withdrawing from outer housing 12.

Inner housing 14 has an axial bore therethrough including a smaller diameter bore 26 at the forward end of inner housing 14 and a larger diameter bore 28 at the rearward end of the housing. Piston 30 is situated within inner housing 14 and includes forward portion 32, of a diameter to fit snugly but slidingly within smaller diameter bore 26, and rearward portion 34, which tapers from forward portion 32 to diameter which fits snugly but slidingly within large diameter bore 28. Actuating member 36 fits within outer housing 12 rearwardly of piston 34 and includes forward extension 38 positioned to act against piston 30 upon operation of actuating member 36. Actuating member 36 can be actuated by any suitable means such as release of high pressure fluid, an explosive charge, release of a cocked spring, etc.

Within a recess of bore 26 adjacent the junction of that bore with bore 28 is located seal 40 which is depicted in enlarged detail in FIG. 2. Seal 49 is retained by retainer 42 which for example can be threadedly connected within bore 28. As illustrated in FIG. 2, seal 40 includes a first portion 44, of a rigid, non-resilient material such as metal, and a second portion 46, of a resilient material such as a hard rubber. Resilient portion 46 is shaped so that no part of non-resilient portion 44 contacts inner barrel member 14. Thus, resilient portion 46 includes a part 48 and may include a radial extension 50 at the forward end of seal 40 extending radially inwardly to bore 26, and an axial extension 52 extending rearwardly from main part 48 at the radial outer edge of seal 40. Chamfer ring 51 prevents portion 46 from extruding between housing 14 and retainer 42. Preferably the interface between resilient portion 46 and non-resilient portion 44 angles with respect to the longitudinal axis of bore 26 to increase the contact area between these two portions.

Barrel 54 extends forwardly from inner housing 14 and is attached thereto, for example by threads. Barrel 54 includes an axial bore 56 having therewithin inner barrel member 58. Axial bore 60 within inner barrel member 58 tapers from a larger diameter at the rearward end of member 58 to a smaller diameter at the forward end. Barrel 54 includes two longitudinal bores 62 and 64 on opposite sides of axial bore 54. Charge inlets 66 and 68 pass radially from bores 62 and 64 respectively to the outer surface of barrel 54, as depicted in FIG. 3. Bores 62 and 64 need not extend forward of inlets 66 and 68 but may do so for ease of manufacture, and if so the forward ends of bores 62 and 64 are closed by plugs 70 and 72, respectively. If desired, a plurality of parallel, or angled bores 60 can be arranged in barrel 54 to produce multiple fluid jets.

Inner barrel member 58 extends radially outwardly at the rearward end of barrel 54 to contact the inner surface of inner housing 14. Longitudinal bores 62 and 64 communicate with bores 74 and 76 through this portion of inner barrel member 58. End member 78 is connected to the rearward end of inner barrel member 58, for example by bolt 80. As seen in FIG. 4, valve zone 82 is defined between end member 78 and the rearward extension 84 of the radially outward portion of inner barrel member 58 and communicates by means of bore 74 and 76 with longitudinal bores 62 and 64. Valve member 86 is located within valve zone 82. End member 78 and the radially outward portion of inner barrel member 58 also define passage 88 which communicates valve zone 82 with axial bore 60. Recess 90 is provided in end member 78 adjacent passage 88.

Valve member 86 is an annular ring fitting snugly but slidingly within valve zone 82. With valve member 86 in its charge loading position, as depicted in FIG. 5, the valve member is at the rearward end of valve zone 82, with its rear face 92 contacting recess 90, and passage 88 is blocked by valve member 86. With valve member 86 in its charge expelling position, as depicted in FIG. 4, the valve member is at the forward end of valve zone 82, with its front face 94 contacting inner barrel member 58. At least one passage 96 passes through valve member 86 for its front face 94 to its rear face 92. Passage 96 serves as a check valve for bore 76 and passes at an angle to, or is offset from, the longitudinal axis of inner housing 14, with passage 96 intersecting front face 94, preferably at a point radially inward from the point at which it intersects rear face 92.

With the components positioned as depicted in FIG. 1, liquid or gel charge material is introduced through charge inlets or bores 66 and 68 and passes through charge transmission passages or bores 62, 64, 74 and 76 to act against valve member 86. The pressure of the charge material causes valve member 86 to move from its position in FIGS. 1 and 4 to its charge loading position of FIG. 5. The charge material then passes through passage 96 to bore 26 within inner housing 14. Should piston 30 be in its forward position adjacent end member 78, the pressure moves the piston to the rearward position of FIG. 1. Bore 26 acts as a charge storage area. Valve 86 in its rearward position blocks passage 88, as seen in FIG. 5, and so charge material cannot enter passage 88 during charge loading.

When charge storage area or bore 26 is filled, actuating member 36 is operated to impact against piston 30. As a consequence, piston 30 moves forward, applying pressure to the charge material within charge storage area or bore 26. This pressure acts against valve member 86, moving the valve member from its charge loading position of FIG. 5 to its charge expelling position of FIG. 4. Since the forward end of passage 96 is not aligned with either passage 74 or passage 76, the charge material cannot pass from charge storage area or bore 26 to charge transmission paths or bores 62 and 64. MOvement of valve member 86 forward interconnects passage 88 with valve zone 82 and thus with charge storage area 26, as seen in FIG. 4. Consequently, under the pressure from piston 30, the charge material is expelled through passage 88 and charge transmission passage or bore to the outlet of apparatus 10. The continually decreasing diameter of charge transmission passage or bore 60 increases the velocity and pressure of the charge material as it exits.

As piston 30 moves forward, pressure in chamber 26 by fluid between piston 30 and housing 14 compresses resilient portion 46 from its rest condition, see FIG. 2, to its compressed condition. Consequently, portion 44 is pressed tightly against piston 30. Therefore, under the high pressure resulting from movement of piston 30, charge material cannot escape from charge storage area 26 past piston 30. I

Continued movement of actuating member 36 results in contact of the actuating member with coupling member 16. Coupling member l6, inner housing 14 and barrel 54 move forward, adsorbing some of the energy of actuating member 36, until rearward end 24 of groove 22 contacts retainer 18.

Valve member 86 thus automatically directs the charge material to the proper passages both during charge loading and during charge expulsion, while seal member 40 provides an extremely tight seal, assuring that charge material does not leak past piston 30 even under the high pressure brought about by movement of the piston.

FIGS. 6a and b and 7a and b illustrate two embodiments of this invention having attachments for angling the fluid jet produced by the apparatus of this invention. In each embodiment, the device for producing the fluid jet, generating generally designated as reference numeral 200, may be a device such as illustrated in FIG. 1. As shown in FIGS. 6a and b a deflection plate 201 is attached to the end of device 200 by support mechanism 202. Deflection plate 201 is arranged at a angle to the fluid jet and contains a slot 204. When using deflection plate 201 the fluid jet will be deflected in the form of a spray. The width of the spray is determined by the width of slot 204 and may be controlled to provide a jet suitable for cutting a slot. Angle a can be as great as to FIG. 7 illustrates an altemative embodiment in which cap 208 is attached to the end of device 200. In this embodiment cap 208 has a number of bores 210 arranged therein in conical fashion about a central opening 212 which is arranged co-axially with the noule in device 200. In this embodiment as the fluid jet passes through cap 208 it is deflected in bore 212 to pass through bores 210. The number of bores 210 can vary from one to any number, e.g. six as shown.

FIG. 8 illustrates another embodiment of the apparatus of this invention. This apparatus differs from FIG. 1 in providing a means for flushing bore 60 to prevent plugging. In this embodiment valve 86 contains a bore 87 interconnected with a high pressure fluid line 91. The device of FIG. 8 operates the same as the device of FIG. 1, described above, except that in its open position valve 86 has moved so that passage 88 is connected through bore 87 with line 91. Fluid pressure line 96 contains check valve 93. Check valve 93 operates upon a reduced pressure in passage 88 to permit the introduction into this passage of fluid, e.g. water or air, under pressure. Fluid passes through bore 87 to flush passage 88 and bore 60. As valve 86 returns to the right in FIG. 8, the pressure in passage 88 will build up to close check valve 93. Also bore 87 is sealed by the interface of valve 86 and extension 84.

FIGS. 9 illustrate an embodiment of this device designed for operation under water. In this device barrel 54 which surrounds member 58 is elongated to form a chamber 85 forward of member 58 and an air pressure line 220 is connected with chamber 85. In operation under water, chamber 85 is always maintained at a sufficient pressure to prevent water, of other fluid media, from entering to reach the forward portion of member 58(Barrel 54 may rest against the surface to be worked or arranged so that the fluid jet passes through from one to three inches of fluid media.

FIG. 10 depicts an embodiment of apparatus similar to that of FIG. 1 but having a plurality of axial-bores 60.

Although the present invention has been described with reference to preferred embodiments, numerous modifications and rearrangements could be made, and still the result would be within the scope of the invention.

What is claimed is:

1. Apparatus for forming pulsed jets of liquid charge material comprising:

a piston;

first means cooperating with said piston to-define a charge storage area having a charge inlet;

a charge expulsion barrel connected to said first means and having an axial bore therethrough communicating with the charge storage area;

valve within the charge storage area, said valve movable in response to pressure in the charge inlet to a first valve position in which the charge inlet is communicatin cou led with th char e stora e area while the iiccele ation bore is blo ked fro m the charge storage area and movable in response to pressure in the charge storage area to a second valve position in which the charge storage area is communicatingly coupled with the acceleration bore while the charge inlet is blocked from the charge storage area;

second means for actuating said piston to apply pressure to the charge storage area; and

seal means sealingly engaging said piston and said first means for providing a substantially fluid-tight seal between said piston and said first means.

2. Apparatus as claimed in claim 1 in which said valve comprises an annular ring engagingly encircling said charge expulsion barrel adjacent the junction of the acceleration bore and the charge storage area and having an opening therethrough in a position unaligned with the charge inlet to permit charge material to pass from the charge inlet through the opening to the charge storage area when said valve is in its first valve position while blocking charge for the charge inlet when the valve is in its second position.

3. Apparatus as claimed in claim 1 in which said seal means comprises an annular seal ring encircling said piston and engaging said first means and including a non-resilient portion and a resilient portion, said first means being engaged only by said resilient portion, said non-resilient portion engaging said piston, whereby upon movement of said piston toward the charge storage area the non-resilient portion is urged against the piston by the resilient portion as the resilient portion is compressed to increased the sealing engagement of said seal about said piston.

4. Apparatus as claimed in claim 1 further comprising flushing means for flushing said expulsion barrel after expelling of the pulsed liquid jet.

5. Apparatus as claimed in claim 4 wherein the flushing means comprises said valve which contains a flushing passage therethrough interconnected with the expulsion barrel when the valve is in said first position and means for supplying pressure fluid to said flushing passage when the valve is in said first position.

6. Apparatus as claimed in claim 1' further comprising a deflection plate attached to the outlet end of said expulsion barrel at an angle to the acceleration bore.

7. Apparatus as claimed in claim 1 further comprising a cap attached to the outlet end of the expulsion barrel, said cap containing at least one bore therein interconnecting with the acceleration bore at an angle to the axis of said acceleration bore.

.8. Apparatus as claimed in claim 1 wherein said barrel contains a plurality of acceleration bores. 

1. Apparatus for forming pulsed jets of liquid charge material comprising: a piston; first means cooperating with said piston to define a charge storage area having a charge inlet; a charge expulsion barrel connected to said first means and having an axial bore therethrough communicating with the charge storage area; a valve within the charge storage area, said valve movable in response to pressure in the charge inlet to a first valve position in which the charge inlet is communicatingly coupled with the charge storage area while the acceleration bore is blocked from the charge storage area and movable in response to pressure in the charge storage area to a second valve position in which the charge storage area is communicatingly coupled with the acceleration bore while the charge inlet is blocked from the charge storage area; second means for actuating said piston to apply pressure to the charge storage area; and seal means sealingly engaging said piston and said first means for providing a substantially fluid-tight seal between said piston and said first means.
 2. Apparatus as claimed in claim 1 in which said valve comprises an annular ring engagingly encircling said charge expulsion barrel adjacent the junction of the acceleration bore and the charge storage area aNd having an opening therethrough in a position unaligned with the charge inlet to permit charge material to pass from the charge inlet through the opening to the charge storage area when said valve is in its first valve position while blocking charge for the charge inlet when the valve is in its second position.
 3. Apparatus as claimed in claim 1 in which said seal means comprises an annular seal ring encircling said piston and engaging said first means and including a non-resilient portion and a resilient portion, said first means being engaged only by said resilient portion, said non-resilient portion engaging said piston, whereby upon movement of said piston toward the charge storage area the non-resilient portion is urged against the piston by the resilient portion as the resilient portion is compressed to increased the sealing engagement of said seal about said piston.
 4. Apparatus as claimed in claim 1 further comprising flushing means for flushing said expulsion barrel after expelling of the pulsed liquid jet.
 5. Apparatus as claimed in claim 4 wherein the flushing means comprises said valve which contains a flushing passage therethrough interconnected with the expulsion barrel when the valve is in said first position and means for supplying pressure fluid to said flushing passage when the valve is in said first position.
 6. Apparatus as claimed in claim 1 further comprising a deflection plate attached to the outlet end of said expulsion barrel at an angle to the acceleration bore.
 7. Apparatus as claimed in claim 1 further comprising a cap attached to the outlet end of the expulsion barrel, said cap containing at least one bore therein interconnecting with the acceleration bore at an angle to the axis of said acceleration bore.
 8. Apparatus as claimed in claim 1 wherein said barrel contains a plurality of acceleration bores. 